<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      * {
        margin: 0;
        padding: 0;
      }
      html,
      body {
        width: 100%;
        height: 100%;
      }
      body {
        background-color: pink;
        display: flex;
        align-items: center;
        justify-content: center;
        flex-direction: row;
      }
      .heart {
        width: 200px;
        height: 200px;
        background-color: #f00;
        position: relative;
        transform: rotate(45deg);
        animation: heartbeat 1s infinite;
      }
      .heart::before {
        content: "";
        width: 200px;
        height: 100px;
        background-color: red;
        position: absolute;
        left: 0;
        top: -100px;
        border-radius: 100px 100px 0 0;
      }
      .heart::after {
        content: "";
        width: 100px;
        height: 200px;
        background-color: red;
        position: absolute;
        left: -100px;
        top: 0;
        border-radius: 100px 0 0 100px;
      }
      @keyframes heartbeat {
        0% {
          transform: rotate(45deg) scale(1);
        }
        50% {
          transform: rotate(45deg) scale(1.3);
        }
        100% {
          transform: rotate(45deg) scale(1);
        }
      }
    </style>
  </head>
  <body>
    <div class="heart"></div>
  </body>
</html>
